Kiln exit gases and the exhaust gases from clinker coolers often cannot be fully utilized in drying plants. In such cases a part of the heat content of the gases should be utilized for water heating. In addition, it is possible to utilize the waste gas heat in conventional steam boilers, with which, depending on design, it is possible to generate electricity at a rate of between 10-30 kWh/t (net output). A new and promising method of utilization of waste gas heat is provided by precalcining systems with bypass, in which up to 100% of the kiln exit gases can be economically bypassed and be utilized in a steam boiler, without requiring any cooling. A development project, already started, gives information on the operational behaviour of such a plant and on the maximum energy recoverable. Alternatively, the bypass gases may, after partial cooling with air or preheater exit gas, be dedusted and then utilized in a grinding/drying plant. Furthermore, they can be used in the cement grinding process for the drying of wet granulated blastfurnace slag or other materials. For this it is not necessary to dedust the bypass gases.